Ortiz-Sánchez Juan Manuel, Bucher Denis, Pierce Levi C T, Markwick Phineus R L, McCammon J Andrew
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0365, United States.
J Chem Theory Comput. 2012 Aug 14;8(8):2752-2761. doi: 10.1021/ct200740r. Epub 2012 Jun 28.
In the present work, we employ excited state accelerated ab initio molecular dynamics (A-AIMD) to efficiently study the excited state energy landscape and photophysical topology of a variety of molecular systems. In particular, we focus on two important challenges for the modeling of excited electronic states: (i) the identification and characterization of conical intersections and crossing seams, in order to predict different and often competing radiationless decay mechanisms, and (ii) the description of the solvent effect on the absorption and emission spectra of chemical species in solution. In particular, using as examples the Schiff bases formaldimine and salicylidenaniline, we show that A-AIMD can be readily employed to explore the conformational space around crossing seams in molecular systems with very different photochemistry. Using acetone in water as an example, we demonstrate that the enhanced configurational space sampling may be used to accurately and efficiently describe both the prominent features and line-shapes of absorption and emission spectra.
在本工作中，我们采用激发态加速从头算分子动力学（A-AIMD）来高效研究各种分子体系的激发态势能面和光物理拓扑结构。特别地，我们聚焦于激发电子态建模的两个重要挑战：（i）锥形交叉点和交叉缝的识别与表征，以便预测不同且常常相互竞争的无辐射衰变机制；（ii）溶剂对溶液中化学物种吸收和发射光谱的影响的描述。具体而言，以席夫碱甲醛亚胺和水杨醛苯胺为例，我们表明A-AIMD可轻易用于探索具有非常不同光化学性质的分子体系中交叉缝周围的构象空间。以水中的丙酮为例，我们证明增强的构型空间采样可用于准确且高效地描述吸收光谱和发射光谱的显著特征及线形。
